I have an 06 Xstar that has been idling funny. It will idle at like 1500 RPMs and when i shift it into gear it will drop down to like 500. I live 4 hours from the nearest dealership. I spoke to two folks who thought it might be a throttle position sensor. Does anyone know if i can get this part at autozone or somewhere like that. It is an 06 Xstar with an MCX engine. I would really appreciate it.

On my Malibu the throttle position sensor had to be calibrated to the ECM once installed. So even if you did get the part you still need to sync them. Example being it reads throttle position from 1-100 and it may come out of the box set at maybe 50 which would be half throttle. It has to be set to your idle speed. Somebody can correct me if I am wrong but that is the way I understood it.

What liter engine do you have? Most likely its going to be the same as the ones off a truck. Your engine is a GM block so most of the parts like the sensors that they use on them are the same. I would take the sensor off, go to the auto parts store and try to see if it matches up.